Wikipedia
Mulyeongari-Oreum
Mulyeongari-oreum is a wetland located in Jeju island. It is the only wetland in Korea which is located on top of oreum. The oreum is one of the secondary volcanoes around Halla mountain which is the highest mountain in South Korea. Through continuing scientific research, it is thought that Mulyeongari-oreum was formed by volcanic activities continuing for 2500 years. The oreum has kept the original status since it was formed and displays a unique example of wetland type. On top of the oreum, there is a shallow crater lake in which the level of water changes by the seasons and this water is just from rainfalls due to the topographical features of Mulyeongari-oreum.